Crush injury

Disease Description (Causes and Symptoms)

• Definition summary: A condition in which part of the body is compressed for a prolonged period by a heavy object or similar force, causing necrosis or damage to muscle, blood vessel, and nerve tissue (crushing injury). In severe cases, it may progress to systemic complications (crush syndrome, rhabdomyolysis, acute renal failure, etc.).
• Main causes: Traffic accidents, construction and mining accidents, collapse accidents (such as earthquakes), occupational accidents, compression by heavy objects, etc.
• Pathophysiology summary: Prolonged compression → muscle ischemia → muscle cell breakdown (rhabdomyolysis) → leakage of intracellular potassium, potamin, myoglobin, etc. → systemic influx of toxic substances upon removal of compression (reperfusion) → electrolyte abnormalities (hyperkalemia), metabolic acidosis, myoglobin-induced kidney injury (acute renal failure), and shock.
• Main symptoms (local and systemic)
  • Local: Severe pain, swelling (edema), tenderness, bruising/subcutaneous bleeding, decreased sensation (numbness/tingling), muscle weakness, weakened or absent peripheral pulse, blisters
  • Systemic: Hypotension and shock, reddish-brown (or dark-colored) urine (myoglobinuria), lethargy, coma, symptoms of electrolyte abnormalities (muscle spasms and arrhythmia)
  • Specific signs related to complications: Rhabdomyolysis (elevated creatine kinase), compartment syndrome (severe pain, tenderness, growing pain, movement and sensory impairment, and tense swelling)

Treatment Methods

• Principles of emergency (initial) treatment
  • Prioritize basic life support (ABCs): Stabilization of the airway, breathing, and circulation
  • When possible, remove the compression as quickly as possible. Before removing the compression, consider administering large-volume fluids (normal saline or lactated Ringer’s solution) to mitigate hypotension and the influx of toxic substances caused by reperfusion (determine priorities according to the scene situation).
  • If bleeding or internal bleeding is suspected, immediately control the bleeding and arrange emergency transport.
• In-hospital treatment
  • Aggressive fluid therapy: Administer an initial large volume of isotonic crystalloid solution (e.g., 0.9% NaCl), followed by maintenance fluids. Secure the target urine output to prevent myoglobin-induced nephrotoxicity.
  • Electrolyte and metabolic management
    • For hyperkalemia: ECG monitoring, calcium (gluconate) for cardiac membrane stabilization, intracellular redistribution with insulin + glucose, and consideration of sodium bicarbonate or a beta-agonist (nebulizer). Hemodialysis is performed in recurrent or uncontrolled cases.
    • Correct acidosis, hyperkalemia, hypocalcemia, and other abnormalities.
  • Management related to rhabdomyolysis (elevated creatine kinase and myoglobin): Consider urinary alkalinization (using sodium bicarbonate) and diuretics (such as mannitol), but use depends on the patient’s condition and institutional guidelines (evidence and contraindications must be checked).
  • If compartment syndrome is suspected, perform fasciotomy immediately.
  • If hemodynamic instability, internal bleeding, or organ damage is suspected, perform emergency surgery (e.g., laparotomy, thoracotomy, vascular and nerve repair, etc.).
  • Fracture management: Reduction and fixation (orthopedic fixation) and infection prevention (broad-spectrum antibiotics in cases of traumatic contamination).
  • Infection prevention: Wound disinfection and drainage, antibiotics if necessary, and tetanus prevention (consider vaccines/immunoglobulin).
  • Perform hemodialysis (including continuous renal replacement therapy) for renal failure or electrolyte abnormalities refractory to correction.
  • Consider amputation in cases of tissue necrosis or irreversible damage (such as anuria, irreversible ischemia, or severe infection).
• Follow-up and monitoring
  • Repeated blood tests: CK, electrolytes, BUN/Cr, blood gases, coagulation tests, CBC, etc.
  • Monitor urine output and color, and perform ECG monitoring (due to the risk of hyperkalemic complications).
• Lifestyle management and precautions (after discharge and during recovery)
  • Visit a medical institution immediately if there are signs of infection (fever or worsening of the wound).
  • Follow-up testing is needed if kidney function abnormalities, changes in urine output, or changes in muscle strength or sensation persist.
  • Restore function through physical therapy and rehabilitation.

Checkpoints Before an Outpatient Visit (Including Example Questions)

• Items to prepare (bring them if possible)
  • List of medications currently being taken (including prescription drugs, nonprescription drugs, and supplements) and allergy records
  • Copies of recent test results (such as blood tests and imaging tests), if available
  • Time of the accident, duration of compression, and photos of the compressed area (if possible)
  • Photos or records of the condition of the wound or fixation devices (such as splints)
  • Records of changes in urine color and amount (e.g., dark brown or reddish-brown)
  • Notes on the timing of changes in pain, sensation, and movement
• Key information to immediately tell medical staff during an outpatient or emergency department visit
  • Duration of compression (minutes/hours)
  • Time of compression release and changes in symptoms immediately afterward (dizziness, severe weakness, changes in urine, etc.)
  • Emergency treatment already administered (fluids, medications, etc.)
• Example questions for the patient to prepare in advance to ask the doctor during an outpatient visit (for reporting to medical staff)
  • “What were my recent CK, creatinine, and potassium levels?”
  • “There has been a change in my urine color (dark brown). Does this indicate a kidney problem?”

Examples of General Questions to Ask the Doctor

• What are the side effects of this medication (the medication administered), and what symptoms should I watch for?
• How should my current test values (potassium, creatinine, CK, etc.) and prognosis be interpreted?
• When can I return to daily activities (exercise, returning to work, etc.)?
• How likely are recurrence and long-term complications (chronic renal failure, nerve damage, etc.)?
• How is the possibility that amputation or additional surgery will be needed determined?

Examples of Disease-Specific Questions

• In my case (based on the duration of compression and current CK and creatinine levels), how likely is it that dialysis will be needed? How is the timing of dialysis determined?
• There are findings suspicious for compartment syndrome. How do you determine whether fasciotomy is immediately necessary?

(Caution: Crushing injuries are often emergencies, so even before a routine outpatient visit, it may be necessary to visit an emergency department immediately and receive emergency treatment.)